Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Are supernovae main sources of interstellar dust? (超新星爆発は星間ダストの主要な供給源か?) Takaya Nozawa (IPMU, University of Tokyo) Collaborators: T. Kozasa, A. Habe (Hokkaido Univ.), K. Maeda, K. Nomoto, M. Tanaka (IPMU), N. Tominaga (Konan Univ.), H. Umeda, I. Sakon (U.T.) 2011/07/07 Outline 1. Introduction 2. Formation and evolution of dust in Type IIb SNe with application to Cassiopeia A SNR 3. Missing-dust problem in core-collapse SNe 4. Formation of dust in the ejecta of SNe Ia 5. Summary 1. Introduction 1-1. Discovery of massive dust at z > 5 quasars ・ The submm observations have confirmed the presence of dust in excess of 108 Msun in 30% of z > 5 quasars ➔ We see warm dust grains heated by absorbing stellar lights in the host galaxies of the quasars *Herschel ・ PACS : 70 μm 100 μm 160 μm SDSS J1148+5251 - age : ~900 Myr (z=6.42) - IR luminosity : ~(1-3)x1013 Lsun - dust mass : (2-7)x108 Msun - SFR : ~3000 Msun/yr (Salpeter IMF) - gas mass : ~3x1010 Msun (Walter+’04) - metallicity : ~solar ・ SPIRE : 250 μm 350 μm 500 μm Leipski+’10, A&A, 518, L34 1-2. What are dust sources in high-z quasars? ・ Supernovae (Type II SNe) ➔ ~0.1 Msun per SN is sufficient (Maiolino+’06; Li+’08) ➔ > 1.0 Msun per SN (Dwek+’07) ・ AGB stars + SNe (Valiante+’09; Dwek & Cherchneff’11) ➔ 0.01-0.05 Msun per AGB (Zhukovska & Gail ’08) ➔ 0.01-1.0 Msun per SN ・ Grain growth in dense clouds + AGB stars + SNe (Draine’09; Michalowski+’10; Pipino+’11; Mattsson’11, Gall+’10, ’11; Valiante+’11) ・ Quasar outflows (Elvis+’02) 1-3. Dust formation in primordial supernovae Supernovae are important sources of dust? ・ Evolution of dust throughout the cosmic age - A large amount of dust (> 108 Msun) in z > 5 quasars ➔ 0.1-1.0 Msun of dust per SN must be ejected - Inventory of interstellar dust in our Galaxy ・ Theoretical studies on dust formation in the SN ejecta (Todini & Ferrara’01; Nozawa+’03; Schneider+’04; Bianchi & Schneider+’07; Cherchneff & Dwek’09, ’10) - Mdust=0.1-1 Msun in (primordial) Type II-P SNe (SNe II-P) - Mdust=1.0-60 Msun in pair-instability SNe (PISNe) its presence has not been proved observationally!! 1-4. Dust destruction in supernova remnants ・ a part of dust grains formed in SNe are destroyed due to sputtering in the hot gas swept up by the shocks (e.g., Bianchi & Schneider’07; Nozawa+’07, ’10) ➔ destruction efficiency of dust depends on the initial size distribution ・ It is necessary to treat formation and destruction of dust self-consistently He core FS RS CD 1-5. Mass and size of dust ejected from SN II-P PISNe SNe II-P total dust mass surviving the destruction in Type II-P SNRs; 0.07-0.8 Msun (nH,0 = 0.1-1 cm-3) size distribution of dust after RS destruction is domimated by large grains (> 0.01 μm) Nozawa+2007, ApJ, 666, 955 at time of dust formation after destruction of dust by reverse shock 2. Formation and evolution of dust in SNe IIb: Application to Cas A 2-1. Dust formation in Type IIb SN ○ SN IIb model (SN1993J-like model) - Meje = 2.94 Msun MZAMS = 18 Msun MH-env = 0.08 Msun - E51 = 1.0 - M(56Ni) = 0.07 Msun 2-2. Dependence of dust radii on SN type SN IIb SN II-P 0.01 μm SN Ib (SN 2006jc) - condensation time of dust (Nozawa+2008) 300-700 d after explosion - total mass of dust formed ・ 0.167 Msun in SN IIb ・ 0.1-1 Msun in SN II-P Nozawa et al. 2010, ApJ, 713, 356 - the radius of dust formed in H-stripped SNe is small ・ SN IIb without massive H-env ➔ adust < 0.01 μm ・ SN II-P with massive H-env ➔ adust > 0.01 μm 2-3. Destruction of dust in Type IIb SNR homogeneous CSM (ρ = const) stellar-wind CSM (ρ ∝ r-2) 330 yr nH,1 = 30, 120, 200 /cc ➔ dM/dt = 2.0, 8.0, 13x10-5 Msun/yr for vw=10 km/s Almost all newly formed grains are destroyed in shocked gas within the SNR for CSM gas density of nH > 0.1 /cc ➔ small radius of newly formed dust ➔ early arrival of reverse shock at dust-forming region Nozawa et al. 2010, ApJ, 713, 356 2-4. IR emission from dust in Cas A SNR AKARI corrected 90 μm image ・ total mass of dust formed Mdust = 0.167 Msun ・ shocked dust : 0.095 Msun Md,warm = 0.008 Msun ・ unshocked dust : Md,cool = 0.072 Msun with Tdust ~ 40 K Nozawa et al. 2010, ApJ, 713, 356 AKARI observation Md,cool = 0.03-0.06 Msun Tdust = 33-41 K (Sibthorpe+’10) Herschel observation Md,cool = 0.075 Msun Tdust ~ 35 K (Barlow+’10) 3. Missing-dust problem in CCSNe 3-1. Difference in estimate of dust mass in SNe ・ Theoretical studies - at time of dust formation : Mdust=0.1-1 Msun in CCSNe (Nozawa+’03; Todini & Ferrara’01; Cherchneff & Dwek’10) - after destruction of dust by reverse shock (SNe II-P) : Msurv~0.01-0.8 Msun (Nozawa+’07; Bianchi & Schneider’07) dust amount needed to explain massive dust at high-z ・ Observational works - NIR/MIR observations of SNe : Mdust < 10-3 Msun (e.g., Ercolano+’07; Sakon+’09; Kotak+’09) - submm observations of SNRs : Mdust > 1 Msun (Dunne+’03; Morgan+’03; Dunne+’09) - MIR/FIR observation of Cas A : Mdust=0.02-0.075 Msun (Rho+’08; Sibthorpe+’09; Barlow+’10) 3-2. Missing-dust problem in CCSNe Tanaka, TN, et al. 2011, submitted theory high optical depth or cold dust ?? grain growth or formation in CDS?? confusion with IS dust?? Middle-aged SNe with ages of 10-100 yrs are good targets to measure the mass of dust formed in SNe!! 3-3. Search for dust in middle-aged CCSNe - silicate - dust temperture ~ 230 K - dust mass ~ 10-3 Msun SN 1978K : Type IIn SNe X-ray bright, massive CSM ➔ the dust is likely to be of circumstellar origin 3-4. Estimate of dust mass in middle-aged SNe Tanaka, TN, et al. 2011, submitted What is temperature of newly formed but unshocked dust? Massive dust can be hidden if Tdust < 100 K 3-5. Temp. of cool dust and its detectability Tanaka, TN, et al. 2011, submitted 0.1 Msun heating sources of dust ・ 44Ti ➔ ~1036 erg/s ・ X-ray emission ➔ < ~1037 erg/s LIR < Ltot < 1037 erg/s ➔ Tdust < 45 K for 0.1 Msun Tdust < 90 K for 10-3 Msun ・ Possible targets SN 1978K, 93J, 04dj, 04et 3-6. Herschel detects massive dust in SN 1987A Matsuura, ..., TN, et al. 2011 to be appeared in Science cool dust in SN1987A theory high optical depth or cold dust ?? grain growth or formation in CDS?? confusion with IS dust?? Herschel detects cool (~20K) dust of 0.4-0.7 Msun toward SN 1987A! 4. Formation of dust in SNe Ia 4-1. Introduction 〇 Type Ia supernovae (SNe Ia) - thermonuclear explosions of C+O white dwarfs with the mass close to Chandrasekhar limit (~1.4 Msun) ・ deflagration (Nomoto+76, 84) ➔ subsonic wave, unburned C in the outer layer ・ (delayed) detonation (Khokhlov91a, 91b) ➔ supersonic wave, burning almost all C - synthesize a significant amount of Fe-peak and intermediate-mass elements such as Si, Mg, and Ca ➔ play a critical role in the chemical evolution ➔ possible sources of interstellar dust? 4-2. Type Ia SNe are sources of dust? 〇 Suggestions on dust formation in SNe Ia - SNe Ia may be producers of Fe grains (Tielens98; Dwek98) - the isotopic signature of presolar type X SiC grains can be explained if produced in SNe Ia (Clayton+’97) 〇 Observations of normal SNe Ia - no increase of IR dust continuum (and no CO emission) - no rapid decrease of the optical light curve - no blueshift of atomic line emissions ➔ these signatures have been reported for CCSNe - no evidence for ejecta-dust in Tycho SNR (Douvion+’01) 4-3. Dust formation in Type Ia SNe ○ Type Ia SN model W7 model (C-deflagration) (Nomoto+’84; Thielemann+’86) - Meje = 1.38 Msun - E51 = 1.3 - M(56Ni) = 0.6 Msun 0.1 Msun of C and O remains unburned in the outermost layer with MC/MO ~ 1 4-4. Dust formation and evolution in SNe Ia average radius Nozawa et al. 2011, ApJ, 736, 45 dust destruction in SNRs 0.01 μm ・ condensation time : 100-300 days ・ average radius of dust : aave <~ 0.01 μm ・ total dust mass : Mdust ~ 0.1 Msun newly formed grains are completely destroyed for ISM density of nH > 0.1 cm-3 ➔ SNe Ia are unlikely to be major sources of dust 4-5. Optical depths by newly formed dust V band (0.55 μm) opacity at 300 days for γ = 1 MC = 0.006 Msun Msilicate = 0.030 Msun MFeS = 0.018 Msun MSi = 0.063 Msun τC = 22 τsilicate = 0.01 τFeS = 14 τSi = 78 Mtotal τtotal = 0.116 Msun = 114 V band (0.55 μm) opacity at 300 days for γ = 0.1 Mtotal ~ 3x10-4 Msun τtotal = 1 Formation of dust grains (C, Si, and Fe) should be suppressed to be consistent with the observations 4-6. Infrared thermal emission from dust Observational data : SN 2005bf at day 200 and 400 (Gerardy+’07) black solid lines : SEDs including emission from C grains ➔ much higher than the observational results red solid lines : SEDs not including emission from C grains ➔ not contradict with the observational results 0.03 Msun of silicate can be allowed as dust mass 4-7. Carbon dust and outermost layer of SNe Ia 〇 Formation of massive carbon dust - high sticking probability of α = 0.1-1 ➔ if α < ~0.01, any dust grain cannot condense - dust formation around 100 days, M(56Ni) ~ 0.6 Msun ➔ dust formation can be destroyed by energetic photons and electrons prevailing in the ejecta - massive unburned carbon (~0.05 Msun) in deflagration ➔ change of WD composition by the He-shell flash ➔ burning of carbon by a delayed detonation wave observationally estimated carbon mass in SNe Ia : Mc < 0.01 Msun (Marion+06; Tanaka+08) 4-8. Dust formation in super-Chandra SNe? - super-Chandra SNe : M(56Ni) ~ 1.0 Msun SN 2009dc, Tarbenberger+’10 detection of CII line ➔ presence of massive unburned carbon enhanced fading at ~200 day ➔ formation of carbon dust? 5. Summary of this talk ・ Size of newly formed dust depends on types of SNe - H-retaining SNe (Type II-P) : aave > 0.01 μm - H-stripped SNe (Type IIb/Ib/Ic and Ia) : aave < 0.01 μm ➔ dust is almost completely destroyed in the SNRs ➔ H-stripped SNe may be poor producers of dust ・ Our model treating dust formation and evolution self-consistently can reproduce IR emission from Cas A ・ Middle-aged SNe with the ages of 10-100 yr are good targets to measure the mass of dust formed in SNe - We detect emission from SN 1978K, which is likely from shocked circumstellar silicate dust with 1.3x10-3 Msun - The non-detection of the other 6 objects seems to be natural because our present search is sensitive only to Ltot >1038 erg/s ・ Mass of dust in young SNRs may be dominated by cool dust ➔ FIR and submm observations of SNRs are essential ➔ Herschel detects massive cool dust toward SN 1987A